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Copyright 2002 General Motors CorporationCopyright 2002 General Motors Corporation

Fundamentals of Fundamentals of HVACHVAC

PPT a7 m01 FinalPPT a7 m01 Final

Fundamentals of Fundamentals of HVACHVAC

PPT a7 m01 FinalPPT a7 m01 Final

Welcome to HVACWelcome to HVAC

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The material contained in this course The material contained in this course component was accurate and current component was accurate and current

at the time of course development.at the time of course development.

The material contained in this course The material contained in this course component was accurate and current component was accurate and current

at the time of course development.at the time of course development.

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ObjectiveObjective

Describe the theory and operation of: HVAC SystemsCooling SystemsAir Distribution SystemsPrinciples of RefrigerationAir Conditioning and ComfortProperties of Heat and Temperature

Describe the theory and operation of: HVAC SystemsCooling SystemsAir Distribution SystemsPrinciples of RefrigerationAir Conditioning and ComfortProperties of Heat and Temperature

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ObjectivesObjectives

Describe the theory and operation of: Vaporization and Condensation Basic Refrigeration cycleFactor Affecting Heat Transfer

Describe the theory and operation of: Vaporization and Condensation Basic Refrigeration cycleFactor Affecting Heat Transfer

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HVACHVAC

Heating

Ventilation

Air Conditioning

Heating

Ventilation

Air Conditioning

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HVAC Sub SystemsHVAC Sub Systems

•Cooling

•Refrigeration

•Air Distribution

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Refrigeration SystemRefrigeration System

CCOTVDOTCCTXVVDTXVTypes of

Refrigerant R-12 R-134A

CCOTVDOTCCTXVVDTXVTypes of

Refrigerant R-12 R-134A

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CCOTCCOT Condenser Accumulator-Dryer Evaporator Muffler Pressure Cycling

Switch Thermostatic Switch Pressure Cut-off

Switch Pressure Sensor

Condenser Accumulator-Dryer Evaporator Muffler Pressure Cycling

Switch Thermostatic Switch Pressure Cut-off

Switch Pressure Sensor

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VDOTVDOT

CondenserAccumulator-DryerEvaporatorMufflerPressure Cut-Off

SwitchPressure Sensor

CondenserAccumulator-DryerEvaporatorMufflerPressure Cut-Off

SwitchPressure Sensor

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CCTXVCCTXV

CondenserReceiver-DryerEvaporatorMufflerThermostatic

SwitchPressure Cut-

Off SwitchPressure

Sensor

CondenserReceiver-DryerEvaporatorMufflerThermostatic

SwitchPressure Cut-

Off SwitchPressure

Sensor

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VDTXVVDTXV

•Condenser•Receiver-Dryer•Evaporator•Muffler•Pressure Cut-Off Switch•Pressure Sensor

•Condenser•Receiver-Dryer•Evaporator•Muffler•Pressure Cut-Off Switch•Pressure Sensor

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Rear UnitsRear Units

Thermostatic Expansion Valve

EvaporatorRefrigerant Lines

Thermostatic Expansion Valve

EvaporatorRefrigerant Lines

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Cooling SystemsCooling Systems

Air Intake

Condenser

Radiator

Fans

Seals and Shroud

Air Intake

Condenser

Radiator

Fans

Seals and Shroud

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Air Distribution SystemAir Distribution System

BlowerEvaporatorHeaterAir DoorsAir DuctsControl

System

BlowerEvaporatorHeaterAir DoorsAir DuctsControl

System

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Principles of RefrigerationPrinciples of Refrigeration

Behaviors of HeatProperties of HeatBehavior of

RefrigerantsEffects of heat and

pressure on liquids and gases

Behaviors of HeatProperties of HeatBehavior of

RefrigerantsEffects of heat and

pressure on liquids and gases

16Air Conditioning and ComfortAir Conditioning and Comfort

MoistureHeatPollenDust

MoistureHeatPollenDust

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Heat versus TemperatureHeat versus TemperatureHeat is measured

in BTUsHeat is the energy

in a substanceTemperature is

measured in degrees

Temperature is the intensity level

Heat is measured in BTUs

Heat is the energy in a substance

Temperature is measured in degrees

Temperature is the intensity level

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Heat TransferHeat Transfer

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Changes in state of matterChanges in state of matter

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Heat of VaporizationHeat of VaporizationA specific amount of

heat is needed to change a liquid to a vapor

Known as latent heatLatent heat of water

970 BTU/lbLatent of 134A

93 BTU/lb

A specific amount of heat is needed to change a liquid to a vapor

Known as latent heatLatent heat of water

970 BTU/lbLatent of 134A

93 BTU/lb

21Vaporization and CondensationVaporization and Condensation

Vaporization is is the addition of latent heat to a liquid

Condensation is the removal of latent heat from a liquid.

Vaporization is is the addition of latent heat to a liquid

Condensation is the removal of latent heat from a liquid.

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Pressure TemperaturePressure TemperatureThe pressure acting

on a liquid is increased, the boiling point of the liquid increases

Lowering the pressure acting on a liquid lowers its boiling point

The pressure acting on a liquid is increased, the boiling point of the liquid increases

Lowering the pressure acting on a liquid lowers its boiling point

23Effects of pressure on gases and vaporsEffects of pressure on gases and vaporsLow pressure low temperature

High pressure high temperature

Low pressure low temperature

High pressure high temperature

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Basic Refrigeration cycleBasic Refrigeration cycle

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Controlling refrigerant flowControlling refrigerant flow

26Factor Affecting Heat TransferFactor Affecting Heat Transfer

Coolant FanCondenserBlower MotorHumiditySun Load

Coolant FanCondenserBlower MotorHumiditySun Load

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SummarySummarySummarySummary

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Copyright 2002 General Motors CorporationCopyright 2002 General Motors Corporation

Fundamentals of Fundamentals of HVACHVAC

Fundamentals of Fundamentals of HVACHVAC

Thank you for attendingThank you for attendingThank you for attendingThank you for attending